Centrifugal process and apparatus



8- 12, 1930. L. D. JONES 1,772,573

CENTRIFUGAL PROCESS AND APPARATUS Filed. April 27, 1929 3 smug-sheet 1 ATTORNEY Aug. 12, 1930. D. JONES 1,772,573

' CENTRIFUGAL PROCESS AND APPARATUS Filed April 27, 1929 s Shets-Sheet 2 law ATTORNEY Patented Aug. 12, 1930 UNITED STATES PATENT OFFICE LEO D. JONES, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE SHARPLES SPECIALTY COMPANY, OF PHILADELPHIA, PENNSYLVANIA, CORPORATION OF DELAWARE Application filed April 27,

This invention relates to a process and heavier substance or constituent in the compartment or passageway so divided off maintains a liquid balance with the contents of the main separating compartment of the rotor. Thus, if water is being separated: from oil, the water in such a separate com partment or passage will balance a stratum of oil and a stratum of water in the main se arating compartment of the bowl. Thus, w en good separation is being effected, separatate strata of the constituents are maintained in the rotor with a relatively distinct dividing line between them. The radial distance of this dividing line, which is actually a cylindrical surface, from theaxis, will be such that it will lie between the light-constituent weir and the radially-outermost edge of the wall that divides the separating compart-ment from the heavy-constituent discharge passage or compartment, that edge being also the radially innermost edge of the passage between that compartment and the discharge passage. The relative distances of the weirs radially inward from thatedge will theoretically determine the point at which that line will lie within the range above described. Various factors will act to cause that line to lie at positions other than the' CENTRIFUGAL PROCESS AND APPARATUS 1929. Serial No. 358,618.

positioned as to ensure a radially thick stratum of the lighter constituent, and vice versa.

A difficulty is that even though the weirs are placed at the proper relative positions, located by trying various adjustments of the heavy-constituent weir, to obtain the desired separation, changes of separating conditions will cause a shifting of the position of the dividing line, and more pronounced changes will cause a discharge of lighter constituent with heavier constituent and lead to a discharge solely through the discharge passage that is intended only for the heavier sub stance. Some of the causes of the changes of separating conditions will be pointed out hereinafter but the causes are not always ascertainable or foreseeable or preventable.

It is an object of this invention to provide a method and apparatus whereby any tendency toward a discharge of excessive volume through the discharge passage through which the heavier substance normally flows, will result in a reaction or resistance or impedance to such flow that will tend to restore or permit the resumption of normal desired conditions of balance within the bowl and normal desired discharge of separated substances.

Within the spirit of my invention various features of operation and construction may be employed to effect such reaction or re sistance or through the disc arge passage for the heavy substance. I disclose herein various features of construction and operation whereby that desired result is attained; and while those specific features constitute parts of my invention, my invention is not limited to those specific features but consists, in its broad aspects, of prevention of excessive'discharge y resisting or impeding or exerting a reaction against, the same y any appropriate feature of construction or operation. However, the various specific features of operation and construction referred to illustrate different applications of the principles of operation of my invention and therefore con im edance to excessive fiow' Ill that an impedance or resistance to or a reaction against the flow of an excessive volume of material through the heavy-constituent discharge of the rotor is produced by centrifugal force. As soon as an excessive flow occurs in that discharge passage an additional or excessive centrifugal force reacts against such flow. The resulting reaction prevents excessive discharge through 'the heavy-constituent discharge, beyond a limited excess, and prevents discharge throu h that outlet to the exclusion of discharge through the light-constituent outlet. Moreover, such reaction creates conditions that facilitate the restoration or resumption of normal separatin conditions.

A eature of my invention is that the above mentioned reaction against'excessive flow in the heavy-constituent discharge passage is effected by causing an abnormal increase in the radial depth of liquid lying in'the heavyconstituent discharge passage and upon which centrifugal force acts. Features of my invention by which this is accomplished, are that the capacity of the heavy-constituent discharge outlet is limited, and the depth to which the crest over the heavy-constituent discharge weir may increase is limited, and the head of liquid acting to balance the contents of the main separating compartment increases more rapidly than it would increase otherwise.

Another feature of my invention is that the above mentioned reaction against excessive flow through the heavy-constituent discharge is effected by causin theliquid flowintensity of reaction due thereto.

ing radially inward tower that discharge to retain, when the flow is excessive, more of the high circumferential or linear speed that it ossesses while it is at,a radially outward is not limited but which embodiments assist in an understandin thereof,

Fig. 1 shows in roken vertical section a centrifugal bowl embodying my invention and whereby my process may be practised;

Figs. 2 and 3rshow details of parts of the 8 is a sectional view on the line 8-8 of i v Figs. 9 and 10 are vertical sectional views, with parts broken away, of a centrifugal bowl embodying a further modification;

Fig. 11 is a vertical sectional viewtaken generally on the line 11-11 of F i 10 but showing a further modification; an

Fig. 12 is a sectional view, with parts broken away, on the line 12-12 of Fig. 11.

Referring first to Fig. 4, there is there shown a construction in which gravity separation may be carried out, and the operation of which will assist in an understanding of the application and operation of my invention in connection with the separation of substances by centrifugal subsidence.

In the construction shown in Fig. 4 grav.--

ity acts downwardly and in the consruction shown in the other figures of the drawin s centrifugal force acts radially outward. n Fig. 4 the substance to be sepomt in the bowl, than is retained when fiow is fed to the main Separating 1snormal, thus causing the liquid in the, discharge passage to effect a greater centrifugal force and a stronger balancing effect when flow is excessive 1n that passage. A feature of my invention whereby this result 1s attained is that an annular discharge passage is provided that leads toward the axis of rotation and in which liquid may possess a higher linear or circumferential speed than the adjacent part of the bowl; and the retarding of such excessive circumferential or linear speed is regulated to produce the desired In such a construction an excessive flow through the discharge passage resultsin a lesser slowing down of the liquid than occurs during normal flow and therefore the liquid in the discharge passage exerts a greater centrifugal force and produces the desired reaction.

In the accompanying drawings, in which there are shown several specific embodiments of the broad fundamental features of my invention, to which embodimentsmy invention partment 14, as by means of a supply pipe 15. By gravity the substance separates into a 1i hter layer 16 and a heavier layer 17.

As t e substance to be separated is supplied head C will decrease and vice versa. If the head A is decreased too much the layer B will disappear and the depth of the li hter sul stance will increase until the. lig ter s'ubstance extends below the point 21, which is the uppermost point of the passage between the separating compartment 'and the lowermost piglint of the wall dividing them, whereupon t e lighter substance will pass into the discharge passage19 and over the weir 20. In an operation 1n which lighter substance is to be freed as far as possible of the'heavier substance the level of the weir 20 is so adjusted that the position of the dividing line eis such that the layer of lighter substance has substantial thickness. If the heavier substance is to be freed as far as possible of the lighter substance, the weir 20 is raised and the e-line is near the weir 18. The level of the weir 20 is so selected that the best separation is effected. If, during the course of a continuous separatingoperation, changes of separating conditions cause the position of the e-line to change, the character of the separation will change. For example the temperature of the mixture supplied may change and there will be a change in the specific gravity of the mixture and of the constituents. Also a change of temperature causes in many instances a change in viscosity and this will change the rate at which effective separation will occur. This change in the eifective rate of separation will also effect a change in the specific gravity of the lighter layer and of the heavier layer due to less complete separation. .Also there may be changes in viscosity that are not necessarily due to temperature changes. There may be variations in the stability of a supplied emulsion or variations in the proportion of emulsion breaking agent present. Also the heavier substance may constitute but a small part of the supplied mixture, and then a leak in the separating apparatus, such as the bowl of a centrifuge, will result in insufiicient heavy material to maintain thenecessary balance. There may be other causes of a change in the rate at which separation will occur. Any cause, some of which can be identified and others of which defy identification, which changes the separating conditions and-causes the li hter constituent to be heavier or causes the eavier constituent to'be lighter or causes both ofsuch re sults. will cause a shifting of the e-line toward the level of the point 21 and cause a leakage of the light constituent into the discharge passage for the heavier constituent. \Vhen the lighter constituent beginsv to pass into the discharge passage 19, the specific gravity of the material in that passage is decreased and there is no longer that balance which will raise the level of the lighter constituent u to the level-of the weir over which it ischarges if head A remains unchanged. In such a case the material in the discharge passage 19, being of reduced spe cific gravity, does not exert sufiicient balancing etiect at the point 21 to cause the material in compartment 16 to rise to the level of weir 18 and nothing will discharge over the weir 18 and all of the substance supplied through pipe 15 tends to flow over weir 20.

In accordance with this invention, features of construction and operation are provided whereby a tendency toward an abnormal rate of flow through the discharge passage for the heavier constituent will automatically effeet a resistance or reaction to or limitation of such excessive flow.

In the construction shown in Fig. 4 the weir 2O constitutes an edge of the slot 22; and if there is a tendency toward excessive flow through the discharge passage 19, the level of. liquid will rise above the weir 20 and form a deeper crest thereon but if that level rises high enough it will attain the level of the upper edge 23 of the slot 22 and any further rise of that level will result in a building up of the head A above the slot 22. Such an in crease in headup to or near the level of weir 18 will insure that there will be a continuance of discharge of lighter substance over the weir 18 and operation may continue with some recovery of the lighter substance even though the heavier substance may be undesir ably contaminated with some of the lighter substance as a result of that upsetting of the balance which caused the excessive discharge throu h the discharge passa e 19. It will he observed that the weir 20 is shorter than the weir 18, and this condition causes the depth of the crest on the weir 20 to increase more rapidly than the depth of the crest on the weir 18 with any increase of rate of flow over the respective weir. The height of the slot 22 is just great enough to take care of the variations in crest on the weir 20 that will occur as a' result of variations in the rate of supply to the bowl. Then any abnormal increase in the flow through the discharge passage 19 will immediately cause a building up of liquid above the edge 23 and a resistance or reaction to excessive flow through thepassage '19. This limitation of the rate of flow through the passage 19 should be such that the flow through that passage must be less than the rate of supply of mixture to the separator. The possible amount by which the flow over weir 20 can exceed the normal flow should be less than the rate at which the light substance is discharged. Intact the rate at which liquid can flow over the weir 20 or through the slot 22 should exceed aslittle as possible the maximum rate at which the heavy substance will discharge during normal operation. The area of the slot 20the effective area for the discharge of the heavier constituent-is so limited that the head A will increase rapidly as soon as there is any tendency for excessive discharge through the dis charge passage for the heavier constituent. A vertical slot might be used. corresponding to a radial slotin a centrifugal rotor and positioned with its upper edge at the level of the edge 23; but when the, slot is horizontal, corresponding to a circumferential slot in a centrifugal rotor, the head of liquid acting on the discharge opening is smaller when flood ing of the heavy discharge weir occurs, than it would be if a radial slot were employed.

In the practice of my invention, in connection with centrifugal separation, the centrifugal force of the'liquid in" the discharge passage, corresponding to the passage 19, is caused to be greater whenever there is a tendency for excessive flow of liquid through that passage. The effect of such a force in a centrifugal bowl is the same asan increase of the head A in the construction shown in Fig. 4.

Referring to Fig. 1, the centrifugal rotor 25 is provided with a feed boss 26 into which mixture to be separated is fed by nozzle 27 A three-wing 28 causes the contents of the bowl to rotate at the same speed as the bowl. The neck 29 -of the bowl is connected to and flows through passage 34 and is discharged from the rotor. The heavier constituent flows around the outer edge 35 of the dividing wall 31 and flows upward through passages 36, of which only one is shown, into an annular passage 37. The discharge of 1i uid from annular passage 37 is controlled by am 38 held in' place by nut 39. Wings 40, of which only one is shown, cause liquid that flows radially inward in the compartment 41 to slow-down to the circumferential speed of the radially inward parts of the rotor to which it flows. The dam 38 is provided with a discharge opening 42 which may be of any size and shape suitable to the practice of this invention. In the construction shown, as illustrated in Fig. 2, this opening is a slot of limited circumferential length and radial width. The edge 43 constitutes a weir that maintains the proper radial depth of heavy constituent in the discharge passage or compartment made up by the passage 36 and the compartment 41, to balance the contents'of the main separating compartment 33 and maintain the dividing line between the separated constituents at a proper radial distance from the axis and between the weir 32 and the edge 35. Inasmuch asthe weir 43 is relativelyshort, an increase of flow through discharge passage 36 will cause the crest of weir 43 to increase rapidly. If conditions of balance are changed, an excessive quantity of liquid, or all of the liquid, tends to flow out of the heavy-substance discharge. Since the capacity of the discharge opening 42 is limited, the level of liquid in the annular chamber 37 will move in toward the axis, and if the level of liquid lies radially inward of the inner edge 44 of the discharge slot 42, then the head of liquid in the discharge passage will be so great that discharge of some light substance over weir 32 will be continued.

The existence of that excessive head will result in such centrifugal force due to liquid in the discharge passage, as will facilitate the restoration or resumption of proper separating conditions, will prevent discharge through the heavy-constituent outlet to the exclusion of the light-constituent outlet, and will cause a constinuance of discharge of some light substances through its proper outlet. ,As soon as mixture of proper consistency, or proper separability, or proper temperature is supplied to the bowl the proper separating conditions and conditions of balance will be restored, and normal operation of the sep arator will be resumed. The weir 32 may have a length bearing any desired ratio to the len h of weir 43, in order that the rate at whic a crest builds up on weir 43 may bear any desired relation to the rate at which a crest builds up on weir 32, when the rate of supply to the bowl is varied. Preferably weir 32 will be as long as possible in order that a crest will build up more rapidly on weir 43. 1

In Figs. 5 to 12 there are shown in cross section only the upper ends of rotors embodying my invention and whereby my process may be practised. In these constructions the resistance to, or impedance of, or reaction against excessive flow resulting from breaking down of proper separating conditions, is derived from centrifugal force, as in the constructions previously described, but, instead of deriving the effective additional centrifugal force in the heavy-constituent discharge passage from extra or excess depth of liquid therein, the additional and eflective centrifugal force is derived fromexcessive rate of rotation of the liquid in the heavy-constituent dischar e passage. In a centrifugal rotor all parts 0 the rotor are rotating at the same number of revolutions perminute but the circumferential speed of each part is proportional to its distance from the axis of rotation- In the construction shown in Fig. 1, wings 40 are located in the compartment 41 and passages 36 are tubular, and the heavy substance flowing from a radially outer point of the bowl toward the axis thereof in said compartment and passages, is slowed down to the circumferential speed of the radially inner point of the bowl to which it flows. Thus each part of the liquid exerts a centrifugal force that is proportional to its distance from the axis.

In accordance with my invention heavyconstituent discharge passages are provided that are annular and do not contain complete radial walls or other features of construction that prevent rotation of liquid therein with respect to the adjacent part of the rotor. Thus when liquid that is at a radially outer point of the bowl and has a high circumferential velocity if flowed radially inward in suchdischarge passages, it retains some of its i high velocity and tends to run ahead of the slower moving inwardly located point of the 'bowl to which it is flowed. Its centrifugal force is therefore not merely proportional to its distance from the axis but it is greater.

The friction of the walls of the discharge passage that extends radially inward, tends to cause a slowing down of liquid flowing inwardly through those passages, to the velocity of the point to which the liquid flows. \Vhen the separating conditions change or the liquid balance in thebowl breaks down the rate of flow through those passages increases, the slowing down is less extensive and the centrifugal force of the liquid in the discharge passages is accordingly greater and effects a resistance or impedance or reaction to such excessive flow. The excess of centrifugal force is in effect like an increase of radial depth of liquid in the discharge passage. In accordance with my invention the width or thickness of such radial discharge passages may be varied to regulate the extent to which friction will slow down substances flowing radially inward therethrough, or, without restricting the radial inflow, the circumferential flow of liquid with respect to the parts may be restricted to varying degress, or the desired result may be obtained both by varying the width or thickness of the passage and restricting the circumferential flow of liquid relatively to the walls of said passage. 1

In the construction shown in Fig. 5 the bowl 25 is provided with a stem 29 having a discharge passa e 134 and a weir 132 for controlling flow of light-constituent through that passage. A dividing wall 131 divides an annular discharge compartment 141 from the separating compartment 33. The heavier substance flows around the edge 135 of wall 131 into discharge passage 141. Upwardly extending tubular passages 136 lead to an may be provided with a heavy-constituent annular chamber 137 and discharge from that chamber-is controlled by dam 138. Dam 138 discharge slot 49 which has the same function and operation as slot 42 and which is proportioned and positioned in accordance with the same principles that determine the proportions and position of slot 20; or, if slot'49 is omitted, liquid flowing from separatingcompartment 33 will discharge over the inner edge of dam 138. Thefannular discharge passage 141 extends from a radially outward point of the bowl to the radially inward passages 136, and it is'free of obstructions that prevent liquid from running ahead of the radially inward parts of the rotor to which it flows as it moves through said passage from radially outward parts of the rotor. Inasmuch aswalls of the passage 141 tend to slow down the liquid to the speed of that part of the rotor to which it flows, the eflect of that friction may be varied by varying the thickthat exceeds the normal flow by a definite amount will so retain its circumferential speed as to exert an excess of centrifugal force which is sufiicient to prevent discharge 'of everything either through slot 49 or over the inner edge of dam 138 in the event that there are indesirable changes in separating conditions, or complete breaking down of liquid balance within the bowl. It thus ap pears that regardless of whether the increase in the balancing effect of the liquid in the dis charge passage is due to the action of cenrifugal force upon an augmented depth of liquid in that passage or due to excessive speeds of rotation of the liquid in that passage, or due to both causes, the result is the same.

In the construction shown in Fig. 5 there is a separate inlet passage 50 for carrier or auxiliary liquid, that leads by way of passage 51 into the rotor, and particularly into the discharge compartment, at a point radially outward of the point at which the heavy constituent is discharged from the rotor. Liquid supplied to the rotor through passages 50 and discharged through slot 49 or over dam 138 will increase the rate of flow through discharge passage 141, with the results above described, thus providing a step and means for regulating the reaction due to flow of liquid through passage 141. Liquid entering passage 50 and flowing into passage 141 will, by increasing the flow in passage 141, cause an increase of over-running and om the separating compartment to the discharge or. balancing compartment or passage and not dependent upon an initiation of improper operation of the separating operation. Also, thisstep and means provide for regulation or restoration of the specific gravity of the contents of the discharge passage. To effect such results either a heavy auxiliary liquid or some of the heavy discharge, as free as possible of light-constituent is introduced into passage 50. The supplying of liquid from an outside or other separate source for the purpose of regulatsa es 141.

ing the flow of liquid through the discharge or balancing compartment or passage, and thereby regulating the centrifugal force or balancing effect or reaction of the liquid therein by varying either the swirling or the radial depth ofthat liquid, or by varyin bot-h the swirlin and radial depth thereo is an im ortant eature of my invention. It is capab e of various applications to produce various results other than those mentioned, such as, for example, the prevention of discharge of oil during the building up of a layer of wax preparatory to centrifugal dewaxing, or the preventionof discharge until a sufficient quantity of a constituent has been accumulated in the rotor to seal the edge 135 of the dividing wall. 1

In order to effect control of the extent to which liquid flowing through passage 141 will swirl in or overrun the rotor as a result of retaining, as it flows to a radially inward point of the rotor, the circumferential velocity that is possessed by it while it is at a radially outward point of the rotor, the wall 131 may be provided with means for regulating or restricting the over-running of the liquid in passage 141. Thus the upper surface of wall 131 may be provided with any suitable number of ridges 52 as shown in Figs. 7 and 8 that are at suitable distance from the upper wall of passage 141. These ridges may be of any desired proportions and so provide adjustable restriction on the overrunning of liquid discharging through pas- By usin ridges of different height the space 53, tween the ridges and the upper wall of passage 141 may be of suitable proportions and suitably restrict circumferential flow of.liquid in passage 141 without restricting radial flow thereof. Obviously, if ridges 52 engage the upper wall of passage 141, or if the discharge passage is otherwise so constructed as to prevent overrunning or swirling of liquid therein, for example as in Fig. 1, liquid introduced into passage 50 will and can only act to increase the radial depth of liquid in the discharge or balancing passage or compartment.

In the construction shown in Figs. 9 to 12 the main separating compartment 33 is divided off from the discharge passages or compartment by means of a wall 231 having an internal weir 132 for the control of-the discharge of lighter constituent. The discharge passages 236 are substantially parallel to the axis of rotation and lead to an annular chamher 237 having a radius substantially as great as the radius of the rotor. Discharge of heavier constituent from chamber 237 is controlled by dam 238 which may or may not be provided with a slot 49. Thus the heavy constituent flows radially inward in chamber 237 from a point at which it has high circumferential velocity to a point at which the rotor has lower circumferential velocity.

The slowin down of the radially inflowing liquid will he dependent upon the width or thickness of the annular chamber 237. The dam 238 is held in place by a nut 239 and by providing and using dams that have the same thickness at the edge and a different thickness elsewhere, as shown in Fig. 10, the depth or thickness of annular chamber 237 may be adjusted.

Also, the underside of the dam 238 may be provided with radial ridges 252 as shown in Figs. 11 and 12, that restrict circumferential flow in annular chamber 237 to a desired extent without interfering with radial flow.

From the foregoing it will be apparent that undesirablechanges in separating conditions, with possible ultimate breaking down of the maintenance of liquid balance that is essential to good separation, will result in an increase of flow through the heavy-constituent discharge passage; and in accordance with my invention an impedance or resistance or reaction to such excess flow is produced by centrifugal force either by causing an abnormally greater depth of liquid to exist in order that the centrifugal force of that greater depth of liquid will produce a reaction, or by causing an abnormally greater rotational speed to act upon a depth of liquid that is the same or only slightly greater, such slightly greater depth being due to any increase of crest on the heavy-constituent weir. The body of liquid that must be in balance with the liquid in the main separating compartment of the rotor in order that proper operation will occur, is the liquid that lies between the outer edge of the dividing wall 31 or 131 or 231 and the weir over which the heavier substance (or heavier substance mixed with auxiliary liquid) discharges; and the balancing effect of this body of balancing liquid is varied by varying the centrifugal force thereof. The centrifugal force thereof is varied by varying the radial depth of that body of liquid or by varying the extent to which that body of liquid retains its rotational speed and overruns radially inward parts of the rotor to which it flows. From the foregoing it is apparent that by limiting the length of the weir over which the heavier substance discharges, as above described, the crest on that weir, and therefore the radial depth of the balancing body, will increase more rapidly with an increase in the rate of discharge over that weir, than would be the case if that weir were an uninterrupted a'nnular edge as in prior practice. The depth of liquid flowing over .that weir will increase when there is any tendency for the discharge of too much liquid thereover, as in the case when conditions of balance break down within the separating compartment; and the depth of liquid flowing over that weir of limited length can be increased to any extent necessary for the maintenance of balance by 1 if the slot 49 is employed in the construcfeeding auxiliary liquid into the balancing body and so increasing the flow of liquid through the balancing body. Thus control of the balancing effect for the purpose of maintaining balance and thereby causing at least some of the substance supplied to the bowl to discharge over both discharge weirs, can be brought about by regulating the supply of auxiliary liquid. And, the limiting of the radiahdimension of the openings 42 and 49 results in more rapid building up of the radial depth of the balancing body; and an increase of flow through the balancing body causes. the liquid of the balancing body, when the balancing chamber is annular and possesses limited resistance to swirling therein, to retain its rotational speed and therefore exert greater centrifugal force and greater balancing effect.

While I have described various modifications of my invention in great detail it is understood that my invention is not limited to such details but includes various modifications of construction and operation involving the principles of my invention and falling within the appended claims. In this connection it is to be noted that certain features of my invention are capable of separate use; and are capable of conjoint use in such a manner as to produce advantages over and above the advantages accruing from the separate use thereof. It is also to be noted that the position of the weir or slot that controls flow through the discharge passage for the heavy constituent, is to be ascertained in accordance with the principles set forth in connection with thedescription of Fig. 4; to the end that liquid balance will be maintained. Obvious-- rate of flow of the substance tobe separated to the influence of centrifugal force, passing a fraction of said substance from the material under the influence of centrifugal force into the radially outward end of said passage and dischargingsaid fraction from the influence of centrifugal force at the radiallyinward end of said passage, and causing excessive flow through said passage to produce a reaction against ence of centrifugal force into the radially outward end of said passage and discharging said fraction from the influence of centrifugal force at the radially inward end of said passage, and causing excessive flow through said passage to increase the centrifugal .force of the liquid therein.

4. In the centrifugal separation of substances by subsidence in a rotor, the steps comprising subjecting the substance to be separated to the influence of centrifugal force. withdrawing a fraction of said substance into a separate body of material also under the influence of centrifugal force and in liquid balance with the main body of material under thewinfluence of centrifugal force, discharging said fraction from the influence of centrifugal force by discharging it from said separate body, and causing an increase in the said fraction from said main tions shown in Figs. 5 and 9. the outer edge/body to said separate body to increase the of that slot will be so positioned as to maintain such balance, and if slot 49 is not usedin those construct-ionsthe inner edge of dams 138 and 238 will be so positioned as to maintain such balance.

I claim:

1. In the centrifugal separation of substances by subsidence in a rotor, the steps com prising s'ubjecting'the substance to be separated to the influence of centrifugal force, passing a fraction of said substance from the ody of material under the influence of centrifugal force at a point of said body radially spaced from the axis of rotation and discharging said fraction from the influence of centrifugal force at a point nearer the axis of rotation, and causing excessive passing of said fraction from said body to produce a reac tion against such passing.

2. In the centrifugal separation of substances by subsidence in a rotor having a discharge passage for a heavier separated constituent leading from a radially outward point of the rotor to a radially inward dis charge point, the steps comprising sub ecting centrifugal force of said separate body.

5. In the centrifugal separation of substances by subsidence in a rotor, the steps comprising subjecting 1 the substance to be separated to the influence of centrifugal force. passing a fraction of said substance from the body of material under the influence ofrentrifugal force at a point of said body radially spaced from the axis of rotation and discharging said. fraction from the influence of centrifugal force at a point nearer the axis of rotation, and by centrifugal force causing an increase of the rate at which said fraction passes from said body to produce a reaction opposed to such passing of sald fraction from said body. y

6. In the centrifugal separation of substances by subsidence in a rotor, the steps comprising subjecting the substance to be sep. arated to the influence of centrifugal force, passing a fraction of said substance from the body of material under the influence'of centrifugal force at a point of said body radially spaced from the axis of rotation and discharging said fraction from the influence of centrif-ugal force at a point nearer the axis of rotation, maintaining that part of said fraction passing from said body to said discharge point in liquid balance with said body, and by centrifugal force increasing such balancing effect of said part of said fraction upon a passing thereto from said body of an excessive quantity thereof.

7.'In the centrifugal separation of substances by subsidence in a rotor, the ste s comprising subjecting the substance to e separated to the influence of centrifugal force, passing a fraction of said substance from the ody of material under the influence of centrifugal force at a point of said body radially spaced from the axis of rotation and disc arging said fraction from the influence of centrifugal force at a point nearer the axis of rotation, maintaining that part of said fraction passing from said body to said discharge point in liquid balance with said body, and increasing such balancing effect of said part of said fraction upon an increase of the rate at which said fraction passes from said body to said part.

8. In the centrifu al separation of substances by subsidence m a rotor, the steps comprising subjecting the substance to be separated to the influence of centrifugal force,

assing a fraction of said substance from the ody of material under the influence of centrifugal force at a point of said body radially spaced from the axis of rotation and discharging said fraction from the influence of centrifugal force at a point nearer the axis of rotation, maintaining that part of said fraction passin from'said body to said discharge point in iquid balance with 'said body, and Increasing the centrifugal force of said part of said constituent upon an increase of the rate at which said fraction passes from saidbody to said part.

9. In the centrifugal separation of substances by subsidence in a rotor, the steps comprising subjecting the substance to be separated to the influence of centrifugal force,

passin a fraction of said substance from the b0 yof material under the influence of centrifugal force at a point of said body radially spaced from the axis of rotation and I dischar 'ng said fraction from the influence of centrifugal force at a point nearer the axis of rotation, and by centrifugal force producing a reaction opposing an increase in'the rate at which said fraction passes from said body to said point of discharge.

10. A centrifugal rotor comprising a separating compartment and having a passage leading from the interior of said compartment at .a radially outer point thereof and open for the discharge of substances at a radially inward point of said rotor, and means whereby centrifugal force produces a reaction to excessive flow of a substance through said passage,

11. In the centrifugal separation of substances by subsidence in a rotor, the steps comprising subjectin the substance to be separated to the in uence of centrifugal force, withdrawing a heavier separated constituent from the body of material under the influence of centrifugal force at a point of said body radially spaced from the axis of rotation anddischarging said heavier constituent from the influence of centrifugal force at a point nearer the axis of rotation and limiting the rate at which material can discharge at said point to substantially the rate at which said constituent is introduced into the influence of centrifugal force.

12. A-centrifugal rotor comprising a separating compartment and havin a passage leading from the interior of said compartment at a radially outer point thereof and open for the discharge of substances at a radially inward point of said rotor, and means limiting the rate of flow through said passage to substantially the rate at which a heavier constituent of a substance fed to the bowl enters the bowl as a part of said substance.

13. A centrifugal rotor comprising a se arating compartment having an inlet an a light-constituent outlet, a balancing compartment having a hGEXY-COIlStltllGIlt outlet and communicating with said separating compartment, and-means for increasing the centrifugal force of the contents of said balancing compartment upon excessive flow of material treated-in said rotor from said separating compartment to said balancing compartment.

14. A centrifugal rotor comprising a separating compartment having an inlet and a light-constituent outlet, a balancing compartment having a heavy-constituent outlet and communicating with said separating comment having a heavy-constituent outlet and communicating with said separating compartment, and means for increasing the balancing effect of material in said balancing compartment upon an increase of the rate of flow thereto from said separating compartment.

16. A centrifugal rotor comprising a sepa rating compartment having an inlet and a light-constituent outlet, and a balancing compartment communicating with said separating compartment at a radially outward point and having a heavy-constituent outlet of limited radial extent. i

17. A centrifugal rotor comprising a separating compartment having an inlet and a light-constituent outlet, and a balancing compartment communicating with'said separating compartment at a radially outward point and having a heavy-constituent outlet of limited capacity; i

18. A cen trifugal rotor comprising a separating compartmenthaving an inlet and a light-constituent outlet, and a balancing compartment communicating with said separating compartment at a radially outward point and having a heavy-constituent outlet having a capacity limited substantially to the rate at which heavy constituent isfed to the rotor in the substance to be separated.

19. In a centrifugal rotor, a separating compartment having an inlet and a lightconstituent outlet, said rotor having a heavysubstance outlet adjacent the axis thereof, and means for passing heavy-constituent from a point of said separating compartment more remote from said axis to said last named outlet and providing for controlled over-running of the rotor by said constituent as it passes "to said last named outlet.

20. A centrifugal rotor having a separating compartment, an inlet and a light-constituent outlet for said compartment, and a passage leading from the interior of said compartment at a radially outward point thereof to a radially inward point of said rotor and having a discharge opening radiailly outward of and adjacent to its inner en s 21. A centrifugal rotor having a separating compartment, an inlet'and a light-con? stituent outlet for said compartment, and

. a passage leading from the interior of said compartment at a radially outward point thereof to a radially inward point of said rotor and having a discharge opening of limited radial extent positioned radially outward of and adjacent to its inner end.

22. In the centrifugal separation of substances by subsidence in a rotor, the steps comprising subjecting the substance to be separated to the influence of centrifugal force, passing a fraction of said substance, from the body of material under the influence of centrifugal force at a point of said body radially spaced from the axis of rotation, inan annular stream, that is circumferentially continuous and substantially concentric with said axis, discharging said fraction from the influence of centrifugal force at a point nearer the circumferentia flow of said fraction in said stream to control the centrifugal force of the materia therein.

231 A centri ugal rotor having a separating compartment, an inlet and a light-sub-' stance'outlet for said compartment, a heavysubstance outletadj acent the axis of the rotor, a circum ferentially continuous annular passage leading from radially outward points of id axis, and regulating" centrifugal force, maintaining under the influence of centrifugal force a second body of liquid which is in communication with said first body of liquid at a point thereof remote from the axis of rotation and which is free to discharge at a point nearer the axis of rotation, causing increase of flow in said separate body toward said point ofdischarge to in crease the centrifugal forceof said separate body, and supplying liquid from an external source tosaid separate body at a radially outward pointthereof at a rate regulated to con-. trol the centrifugal force of said separate body of liquid.

25. In the centrifugal separation of sub-.

stances by subsidence in a rotor, the steps comprising subjecting the substance to "be separated to the influence 'of centrifugal force, passing a part of said substance from the body thereof that is under the influence of centrifugal force at a point of said body radially spaced from the axis of rotation and discharging said part from the influence of centrifugal force at a point nearer the axis of rotation, causing the centrifugal force of liquid so flowing to said point of discharge to increase upon-an increase in the rate of flow thereof, and adding to the liquid so flow ing a quantity of auxiliary liquid regulated to control the centrifugal force of that body of liquid.

26. In the centrifugal separation of sub stancesby subsidence in a rotor having a discharge passage for a heavier separated constituent leading from a radially outward point of the rotor to a radially inward discharge point, the steps comprising subjecting the substance to be separated'to the influence of centrifugal force b passing it into the rotor, causing excessive ow through said passage to increase the centrifugal force of the liquid therein, and adding to the liquid flowing in said passage 3. quantity of auxiliary liquid regulated to control the centrifugal force of the liquid in said passage and thereby controlling the discharge of the substance or its constituents through said pas sa e. I

7. In the centrifugal separation of substances by subsidence in a rotor having a di'sthe rotor, causing flow of liquid through said passage to produce a reaction against a flow provided with means whereby variations in the rate of supply of liquid to said passage cause substantially corresponding variations in the centrifugal force of the liquid therein, and an auxiliary liquid inlet for supplying liquid to a radially outer point of said passage.

stances by subsidence in a rotor, the steps comprising maintaining a main body of the substance and a balancing body of liquid under the influence of centrifugal force and in communication at a point radially spaced from the axis of rotation and discharging liquid from each of said bodies-mespectively at points radially inward of saidpoint of communication, and by centrifugal force causing excessive flow through said balancing body to increase the balancing effect of said balancing body sufficiently to ensure continuous discharge from said main body at said point of discharge therefrom.

30. In the centrifugal separation of substances by subsidence in a rotor, the steps comprising maintaining a main body of the substance and a balancing body of liquid under the influence of centrifugal force and. in communication at a point radially-spaced from the axis of 'rotation and discharging liquid from each of said bodies respectively at points radially inward of said point of communication, and by varying the flow through said balancing body varying the balancin effect of said balancing body.

31. n the centrifugal separation of substances by subsidence in a rotor, the steps comprising maintaining a main body of the substance and a balancing body of liquid under the influence of centrifugal force and 29. In the centrifugal separation of subfrom the axis of rotation and discharging liquid from each of said bodies respectively at pointsradially inward of said point of communication, and causing variations in the rate of flow of liquid through said balancing body to maintain the balancing eflect thereof at such value that some of the substance will continuously discharge at bothof said discharge points.

33. In the centrifugal separation of substances by subsidence in a rotor, the steps comprising subjecting the substance to the action of centrifugal force to effect separation thereof into its constituents, separately discharging the separated constituents, and causing excessive discharge of the heavier of the constituents to produce sufiicient reaction tosuch discharge to maintain continuous discharge of the lighter cons'tituentduring substantially uniform supply of the substance.

34. In the centrifugal separation of substances by subsidence in a rotor, the steps comprising maintaining a main body of the substance and a balancing body of liquid under the influence of centrifugal force and in communication at a point radially spaced from the axis of rotation, continuously feeding to said main body the substance to be se arated, discharging liquid from each of said bodies respectively at points radially inward of said point of communication, causing variations in the rate of flow of liquid through said balancing body to said point of discharge therefrom to vary the balancing efiect thereof upon said main body, and adding to the liquid flowing through said balancing body a quantity of auxiliary liquid regulated to control the balancing effect ofsaid balancing body and thereby controlling the rate of discharge from said discharge pointof said balancing body.

In testimony whereof, I have signed my name to this specification.

LEO D. JONES.

in communication at a point radially spaced from the axis of rotation and discharging liquid from each of said bodies respectively at points radially inward of said point of communication. and causing variations in the rate of flow of li uid through said balancing body'to vary the alancing efi'ect thereof.

32. In the centrifugal separation of substances by subsidence in a rotor, the steps comprising maintaining a main body of the substance an'd-a balancing body of liquid under the influence of centrifugal force and in communication at a point radially spaced 

